1. Field of the Invention
The present invention relates to an optical device wafer processing method for transferring an optical device layer in an optical device wafer to a transfer substrate, the optical device layer being composed of an n-type semiconductor layer and a p-type semiconductor layer, formed on the front side of an epitaxy substrate such as a sapphire substrate and a silicon carbide substrate through a buffer layer, and partitioned by a plurality of crossing streets to define a plurality of regions where optical devices such as light emitting diodes and laser diodes are respectively formed.
2. Description of the Related Art
In an optical device fabrication process, an optical device layer composed of an n-type semiconductor layer and a p-type semiconductor layer is formed on the front side of a substantially disk-shaped epitaxy substrate such as a sapphire substrate and a silicon carbide substrate through a buffer layer, and this optical device layer is partitioned by a plurality of crossing streets into a plurality of regions where a plurality of optical devices such as light emitting diodes and laser diodes are respectively formed, thus constituting an optical device wafer. The optical device wafer is divided along the streets to thereby obtain the individual optical devices (see Japanese Patent Laid-open No. Hei 10-305420, for example).
Further, as a technique for improving the luminance of an optical device, a manufacturing method called lift-off is disclosed in JP-T-2005-516415. In an optical device wafer, an optical device layer composed of an n-type semiconductor layer and a p-type semiconductor layer is formed on the front side of an epitaxy substrate such as a sapphire substrate and a silicon carbide substrate through a buffer layer. The above-mentioned method called lift-off includes the steps of bonding the optical device layer of the optical device wafer through a bonding metal layer formed of gold (Au), platinum (Pt), chromium (Cr), indium (In), or palladium (Pd) to a transfer substrate formed of molybdenum (Mo), copper (Cu), or silicon (Si) and next applying a laser beam from the back side of the epitaxy substrate to the buffer layer to thereby peel off the epitaxy substrate, thus transferring the optical device layer to the transfer substrate.